The chemistry, biochemistry and pharmacology of biogenic amines, their amino acid precursors and transformation products have been investigated. The areas of specific interest are: 1) the immunolocalization of catechol-O-methyltransferase (COMT) in malignant and normal human and rodent tissues. 2) The effect of the substitution of fluorine on the aromatic ring of dopamine, norepinephrine, and serotonin and their amino acid precursors on the biological properties of these compounds. 3) The mechanism of toxicity and leukocytopoiesis of 2-fluorohistidine in normal and leukemic mice, and the metabolism and incorporation into protein of 2-fluorohistidine in vivo and in vitro. 4) The behavioral and neurochemical characterization of the tryptophan-deficient rat.